
package de.unihannover.se.restlab.microblog.providers;

import java.io.IOException;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.Arrays;

import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;

import de.unihannover.se.restlab.microblog.models.Message;

@Provider
@Produces(MediaType.TEXT_PLAIN)
public class PlainMessageListWriter implements MessageBodyWriter<Message[]> {

	@Override
	public long getSize (Message[] t, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
		return -1;
	}

	@Override
	public boolean isWriteable (Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
		return (type.getName().equals("[L" + Message.class.getName() + ";"));
	}

	@Override
	public void writeTo (Message[] t, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType,
		MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) throws IOException, WebApplicationException {

		if (t.length == 0) {
			entityStream.write("List of messages is empty!".getBytes());
		} else {
			for (Message message : Arrays.asList(t)) {
				entityStream.write((message.getUser().getId() + ";" + message.getCreatedAt() + ": " + message.getContent() + "\n")
					.getBytes());
			}
		}

	}

}
